Sift flour and sugar. Heat butter, cocoa and coca-cola to boiling; pour over sugar mixture. Mix buttermilk, eggs, baking soda, marshmallows and vanilla; add to mixture. Mix well; batter will be thin. Pour into greased and floured 9x13 inch pan. Bake 30 minutes at 350 degrees.
1 c. margarine
3 tbsp. cocoa
6 tbsp. coca-cola
1 (16 oz.) box powdered sugar (sifted)
1 c. nuts
1 tsp. vanilla
Combine margarine, cocoa, coca-cola and heat to boiling. Pour over sugar. Blend with mixer until smooth. Add nuts, vanilla. Pour over cake while frosting is hot.